package practice.w910;

public class ToUpperCaseDemo {
    public static void main(String[] args) {
        String str = "我爱Java!";
        String upper = str.toUpperCase();
        System.out.println(upper);
        String lowerStr = str.toLowerCase();
        System.out.println(lowerStr);

//        String str = "我爱Java!";
//        String upper = str.toUpperCase();
//        System.out.println(upper);
//        String lowerStr = str.toLowerCase();
//        System.out.println(lowerStr);
    }
}
